How to choose mould steel for Mould buyers

Plastic mould steel, namely tool steel is used for making injection mould, which is a kind of moulds suitable for plastic products moulding. The choice of mould steel has a direct effect on the quality of the mould, absolutely it will affect the quality of plastic products. Mould buyers can consider the mould life, plastic material and so on to choose mould material which is suitable for your plastic products. Certainly, you should listen to mould suppliers’ proposal.

You can choose mould steel according to plastic mould life. Mould life can be divided into four levels:

1 Above one million shots.

2. 500,000 to 1,000,000 shots

3 300,000 to 500,000 shots

4 100,000 to 300,000 shots

5 less than 100,000 shots

General speaking , moulds ,which can be used 500,000 shots, are required to have hardness number about HRC50 , have good ability of heat treatment and cutting performance. When making The third stage mould, you can choose 718H, 083H, S136H, 2316H etc. For fifth class mould, you can choose P20, 718, 738 etc. Most home appliance moulds belong to fourth or fifth plastic moulds. For special low requirements moulds, 45# is also ok.

To choose mould materials according to the materials of plastic products . While plastic material occurring plastic degeneration in the cavity, the plastic material is sliding and flowing along the cavity surface. This process can lead to severe friction between the cavity surface and the plastic products. Mould will be unavailable because of wear. So the wear resistance of mould steel is one of the most fundamental and most important performances. Hardness is the main factors which influence the wear resistance. Some plastic materials are acid corrosive, and some mixed with enhancers or Modification agent, for example glass fiber, which can make great wear to moulds. So when using these kinds of plastic materials, mould steel must has high hardness. The appearance of the plastic products also has a great influence on the choice of mould steel. For example, transparent Refrigerator parts mold and high Surface requirements products can choose 718S, S136, 2316, 420, PAK80. For high transparency plastic products , you should choose steel S136 or 420.